Rhythmic Like Heartbeats
by you-idjits
Summary: "Dean and Castiel don't get together all of a sudden. There's no dramatic confession, no obvious morning-after. It's slow, it's quiet. Friendship blurs into something more, and Sam can no longer see the difference." After the events of 8.23 Sacrifice, Dean and Castiel fall in love. Sam watches quietly.


Sam figures it out on October 8, 2013. It's when he and Dean finally find Cas, after the initial aftershocks of the Fall, and he immediately falls into Dean's arms. Dean cries and tries desperately to hide it. Castiel just shivers and holds on tighter.

Sam's made jokes about the two of them before; they have a habit of staring into each other's eyes that's just begging to be mocked. But this, this is when he realizes it's something more. Dean _needs_ Cas.

Dean loves Sam, and he's always needed Sam, but this is different. Sam sees it in Dean's eyes. This is a different kind of bond.

Dean's always been thickheaded about this kind of thing, and Castiel is, well, Castiel. Sam wonders if he's the first one to see the bond. But things progress quickly after that.

Dean and Castiel don't get together all of a sudden. There's no dramatic confession, no obvious morning-after. It's slow, it's quiet. Friendship blurs into something more, and Sam can no longer see the difference.

Neither Dean nor Castiel explicitly tells Sam anything. They almost seem to be hiding it, sneaking stolen kisses when they think he isn't looking. But Sam sees, and he respects their privacy.

Things are still difficult. Castiel is human now, and he runs the whole gamut of emotions from angry to anxious to absent. He's rough around the edges now. And Dean still stubbornly tries to bottle up his emotions. Sam's left reeling from the trials. The three of them will never be perfect.

But Dean is _happy_. Maybe not all the time; the life is stressful. It's never been sunshine and rainbows. But when Sam sees Dean with Castiel, he looks changed. He's quieter, calmer.

Dean never sought happiness. He always valued others' needs above his own, always did what needed doing because it was _right_, not because he wanted to. He spent years stopping one Apocalypse after the other, without so much as a thank-you. But somehow, he stumbled across his own happiness in the form of a fallen angel with eyes just a little too blue.

They hold hands under the table at diners, and Sam pretends not to notice.

One night, after a particularly nasty hunt, Castiel stitches up a gash in Dean's side with such care, such gentleness, it's as intimate as making love. Sam can't help but avert his eyes.

Dean stops going to bars after hunts. He drinks less.

On warm days, Castiel trades his trench coat for one of Dean's faded t-shirts.

Sam sees the way Dean worries after Castiel. During hunts, his eyes linger on Castiel for far too long, concern shining through his eyes. Dean has always worried about Sam – that's his job – but never like that. Never with such gentleness. Dean is afraid Castiel will break.

During one hunt, Castiel almost dies. When they make it back to the motel, tired and bloody, Sam heads for the nearest drugstore for a supply run.

Upon his return, he hesitates, cracks open the door, and searches the darkness for his friends. He knows what to expect.

The bed creaks with desperation and stifled moans, rhythmic like heartbeats.

Sam closes the door quietly and goes to sleep in the car.

Now that Castiel lives with them permanently, this isn't an uncommon occurrence. They play rock-paper-scissors for the two beds, and the unlucky third sleeps on the floor, or in the car. On some nights, when Sam goes to bed early, he wakes up to see Castiel curled up in bed with Dean, sheets and limbs knotted together.

He considers just telling them, _it's okay if you guys want to share a bed, I don't mind_, but that would be acknowledging their relationship, and the words can go unsaid.

Car rides become easier, with three. They take shifts – one sleeping in the back, one driving, and one riding shotgun. Sometimes, even when he's not tired, Sam takes the backseat just to give Dean and Castiel their privacy. He hears their murmured words and it lulls him to sleep.

He doesn't mind sharing his brother. Sometimes, Dean cares too much. It's about time someone cared for him.

Sam has always leaned on his brother, in times of trouble. Now, though, he's thirty years old. He can stand tall and straight on his own.

Dean and Castiel protect each other, guide each other. Dean and Cas. Cas and Dean.

Sam lets them be.


End file.
